diff --git a/src/neighbors.f90 b/src/neighbors.f90
index e66392f..6e81c38 100644
--- a/src/neighbors.f90
+++ b/src/neighbors.f90
@@ -94,6 +94,8 @@ module neighbors
         end if
 
         allocate(nei_list(100,n),nei_num(n))
+        nei_list=0
+        nei_num=0
 
         !Now first pass the position list and and point num to the cell algorithm
         call build_cell_list(n, r_list, rc_off, cell_num, num_in_cell, cell_list, which_cell)